Combustion apparatus for gas turbine engines



Dec.2, 1969 SRJACKSON Em. 3,481,146

COMBUSTION APPARATUS FOR GAS TURBINE ENGINES Filed Dec. 28, 1967 4 Sheets-Sheet 1 Dec. 2, 1969 s. R. JACK-SON ETAL 3,481,146

COMBUSTION APPARATUS FOR GAS TURBINE ENGINES Filed Dec. 28, 1967 4 Sheets-Sheet 1969 s. R. JACKSON ETAL 3,481,145

COMBUSTION APPARMUS FOR GAS TURBINE ENGINES rue: Dec. 28. 1967 4 Sheets-Sheet s Dec. 2, 1969 s. R. JACKSON ETAL 3,481,146

COMBK JSTION APPARATUS FOR GAS TURBINE ENGINES mu m. 28. 1967 4 Sheets-Sheet 4 Unitedtes Patent" U.S. Cl. 6039.32 Claim ABSTRACT OF THE DISCLOSURE Combustion apparatus for gas turbine engines comprises a plurality of flame tubes spaced angularly about the engine axis, each flame tube, at its upstream end being mounted for sliding and pivotal movement, the downstream end being connected to supporting structure through a link connected with its axes generally tangential with respect to a circle the centre of which lies on the engine axis, the link being on the inner side of the flame tube and overlapping flanges on the flame tube and supporting structure.

This invention relates to combustion apparatus for gas turbine engines and of the kind comprising a plurality of flame tubes spaced angularly about the longitudinal centre line of the engine, to a first or upstream end of each of which air can be supplied from a compressor, means being provided for supplying liquid fuel to the flame tubes, and from the opposite or downstream end of the flame tubes the products of combustion can be discharged through a turbine.

The parts of the combustion apparatus are subjected, in use, to considerable temperature changes, and it has therefor been proposed to mount the flame tubes on supporting structures of the engine in such a way that stressing due to dilferentialy thermal expansion and contraction is minimised.

The object of this invention is to provide combustion apparatus, in a convenient form, which permits of some relative movement between the flame tubes and the supporting structure, to minimise stressing.

According to the present invention, in combustion apparatus of the kind specified, each flame tube is mounted on supporting structure of the engine, at its upstream end for sliding movement longitudinally of the flame tube as connected at one end of the flame tube, and its other end well as for limited pivotal movement of the flame tube about its upstream end, the downstream end being connected to the suporting structure through a link pivotally connected at one end to the flame tube, and its other end connected to the supporting structure, the axes of the pivotal connections being generally tangential with respect to a circle, the centre of which coincides with the engine centre line, said link being disposed at the inner side of the flame tube with respect to the engine centre line. and overlaping flanges on the flame tube and on the supporting structure respectively, at the downstream end, permitting relative movement of the flame tube and the supporting structure.

The invention will now be illustrated by way of example with reference to the accompaning drawings in which:

FIGURE 1 is a diagrammatic cross-sectional side elevation view taken on a radial plane of a gas turbine engine,

FIGURE 2 is a view on arrow II in FIGURE 1,

FIGURE 3 is a similar view to FIGURE 1 showing an alternative arrangement, and

3,481,146 Patented Dec. 2, 1969 FIGURE 4 is a cross-sectional view on the line IV-IV in FIGURE 3. I In the example shown in FIGURE 1 and 2, there is provided a gas turbine engine having a plurality of flame tubes disposed equi-angularly about the engine centre line, each flame tube, one of which is shown in FIGURE 1 and indicated by numeral 10, is arranged to receive air at its upstream end, from a compressor (not shown) and arranged to discharge the products of combustion from its downstream end, through an annular discharge duct 11, to a turbine (not shown).

Each flame tube is mounted on the engine, at its upstream end, by means of a liquid fuel burner nozzle 12 incorporating a part-spherical bearing 13 to permit of limited pivotal movement of the flame tube about its upstream end. The flame tube 10 is also slidable longitudinally relative to the burner nozzle 12.

The downstream end of each flame tube is connected, at its inner side, with respect to the engine centre line, to supporting structure 14 of the engine, by a link 15 pivotally connected at one end to the flame tube 10 and at the other to the supporting structure '14, the axes of the pins 16, 17 forming the pivotal connections being generally tangentially with respect to a circle, the centre of which coincides with the engine centre line. Each link 15 is forked at both ends. One pair of forks receives a pair of lugs 18 fixed respectively to a pair of adjacent flame tubes, these parts being connected thereto by the pin 16. The other pair of forks of the link 15 receives a lug 19 fixed to the supporting structure 14. These are connected by the pin 17. With this arrangement the link serves to secure together a pair of adjacent flame tubes 10.

The flame tubes which are of circular cross-section are arranged to be connected to the annular discharge duct 11 and the downstream end of each flame tube 10 merges into the annular form at or near the junction with the discharge duct 11. The adjacent flame tube wall portions join to form a portion which is concave as viewed in a radial plane with respect to the centre line of the engine and convex as viewed in a plane perpendicular to said radial plane. The junctions between the adjacent flame tubes, as well as the junctions between the flame tubes and the discharge duct, include overlapping flanges 20, 21 which permit of relative movements, in response to differential expansion and contractions of the parts.

In a modified form of the invention shown in FIG- URES 3 and 4, the downstream end portions of the flame tubes 10 are separate from the upstream end portions, these portions being bolted together, as shown in FIG- URE 4. The downstream end portions serve as transitional portions from circular cross-section to segmental crosssection, merging into the annular shape of the discharge duct 11 in this downstream end portion.

With the arrangement of this invention, the flame tube downstream ends can move radially of the engine under the control of the links 15 and also to a limited extent, longitudinally, as radial movement occurs. The provision of the links aflord hinge connections at the downstream ends of the flame tubes respectively. There is described and claimed in the complete specification of our copending British patent application No. 23,560/ 64, a further form of such a hinge connection.

Having thus described our invention what we claim as new and desire to secure by Letter Patent is:

1. Combination apparatus for a gas turbine engine comprising supporting structure for a plurality of flame tubes spaced angularly about a longitudinal center line of the engine, an inlet at the upstream end, and an outlet at the downstream end of each of the flame tubes 0 respectively, liquid fuel delivery means to the upstream ends of the flame tubes respectively, each flame tube being mounted on the supporting structure, at its upstream end to permit longitudinal'sliding movement of the flame tube, as well as limited pivotal movement of the flame tube about its upstream end, the downstream end being connected ftofthe supporting structure through a link pivotally connected at one end to the flame tube and at.

its other end to the supporting structure, the axes of the pivotal connection being generally tangential with respect to a circle, the center of which coincides with the engine center line, said link being disposed at the inner References Cited UNITED STATES PATENTS 2,268,464 12/1941 Seippel 60-3965 2,511,432 6/1950 Feilden 60-3932 FOREIGN PATENTS 1,026,645 4/ 1966 Great Britain.

0 MARK NEWMAN, Primary Examiner D. HART, Assistant Examiner 

